Funding for this research was provided by:
Japanese Orthopaedic Association Grants-in-Aid for Scientific Research (2017-3)
Text and Data Mining valid from 2019-08-28
Received: 19 February 2019
Accepted: 14 August 2019
First Online: 28 August 2019
Compliance with ethical standards
: The authors declare that they have no competing interests.
: The ethics committee for human research at our hospital approved the study protocol, and informed consent to undergo an examination and operation was obtained from all patients. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
: Informed consent was obtained from all individual participants included in the study.